/Engine/Plugins/Online/OnlineSubsystemUtils/Source/OnlineSubsystemUtils/Public/VoiceEngineImpl.h
Registers the unique player id as a remote talker (submitted voice data only)
0 upon success, an error code otherwise
virtual uint32 RegisterRemoteTalker ( const [FUniqueNetId](API\Runtime\CoreOnline\Online\FUniqueNetId) & UniqueId )